Fix Xcode Cloud UI tests by running TestAction in Debug (#672)

* Set cmux TestAction to Debug for UI tests

* Broaden XCTest detection for debug launch gate

* Fix AutomationSocketUITests launch hang in CI

* Stabilize CI Swift package resolution for test jobs

* Stabilize Xcode Cloud UI test focus and socket handling

* Add Xcode Cloud pre-xcodebuild submodule bootstrap

* Harden Xcode Cloud bonsplit bootstrap fallback

.github/workflows/ci.yml

@@ -22,6 +22,9 @@ jobs:
       - name: Validate unit-test SwiftPM retry guard
         run: ./tests/test_ci_unit_test_spm_retry.sh
 
+      - name: Validate cmux scheme test configuration
+        run: ./tests/test_ci_scheme_testaction_debug.sh
+
   web-typecheck:
     runs-on: ubuntu-latest
     defaults:
@@ -96,11 +99,35 @@ jobs:
           # Remove stale build cache to avoid incremental build errors
           rm -rf ~/Library/Developer/Xcode/DerivedData/GhosttyTabs-*
 
+      - name: Resolve Swift packages
+        run: |
+          set -euo pipefail
+          SOURCE_PACKAGES_DIR="$PWD/.ci-source-packages"
+          rm -rf "$SOURCE_PACKAGES_DIR"
+          mkdir -p "$SOURCE_PACKAGES_DIR"
+
+          for attempt in 1 2 3; do
+            if xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux-unit -configuration Debug \
+              -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
+              -resolvePackageDependencies; then
+              exit 0
+            fi
+            if [ "$attempt" -eq 3 ]; then
+              echo "Failed to resolve Swift packages after 3 attempts" >&2
+              exit 1
+            fi
+            echo "Package resolution failed on attempt $attempt, retrying..."
+            sleep $((attempt * 5))
+          done
+
       - name: Run unit tests
         run: |
           set -euo pipefail
+          SOURCE_PACKAGES_DIR="$PWD/.ci-source-packages"
           run_unit_tests() {
             xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux-unit -configuration Debug \
+              -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
+              -disableAutomaticPackageResolution \
               -destination "platform=macOS" test 2>&1
           }
 
@@ -138,4 +165,9 @@ jobs:
       - name: Run UI tests
         run: |
           set -euo pipefail
-          xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug -destination "platform=macOS" -only-testing:cmuxUITests/UpdatePillUITests test
+          SOURCE_PACKAGES_DIR="$PWD/.ci-source-packages"
+          xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug \
+            -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
+            -disableAutomaticPackageResolution \
+            -destination "platform=macOS" \
+            -only-testing:cmuxUITests/UpdatePillUITests test